Delayed mobile node registration with home agent

ABSTRACT

Mobile node registration with the home network of the mobile node is delayed when the mobile node moves to a foreign network. The mobile node has a home network in which the mobile node has a home address. In response to the mobile node moving to a foreign network (such as by being turned on in the foreign network), the mobile node receives a care-of address. Where the mobile node has no ongoing communication sessions, the mobile node waits to register its care-of address with its home agent in the home network until the mobile node initiates a communication session within the foreign network, which may not ever occur. The mobile node by registering the care-of address with the home agent informs the home agent where to forward data sent to the mobile node&#39;s home address.

FIELD OF THE INVENTION

The present invention relates generally to mobile nodes having homeagents with which they are to register when entering foreign networks,and more particularly to such mobile nodes delaying registration withtheir home agents when entering foreign networks.

BACKGROUND OF THE INVENTION

Traditionally, resources, such as computing devices and other types ofdevices, which had Internet connectivity were stationary while connectedto the Internet. For instance, a desktop computer that is able toconnect to the Internet is deployed at a given location for anindefinite period of time. Even a laptop computer, which is considered aportable device, is usually stationary while connected to the Internet.That is, the laptop computer may be moved from one location to another,but while the laptop computer is connected to the Internet, it typicallyremains at a given location.

More recently, other types of resources, such as cellular and mobilephones, personal digital assistant (PDA) devices, and other types ofdevices, including laptop computers, have Internet connectivity in whichthe resources are mobile while connected to the Internet. For example, amobile phone may be connected to the Internet, while the phone is beingmoved from one location to another. The user of the mobile phone may bein a car, a train, or simply walking around.

To provide for Internet connectivity in which resources are mobile whileconnected to the Internet, a given mobile resource, which is alsoreferred to as a mobile node herein, may have a home address within ahome network, and receive care-of addresses while in foreign networks,which are networks other than the home network. For example, a mobilephone may have a home cell, or network.

When the mobile phone is transported to a different cell, which is aforeign network, the mobile phone receives a care-of address that it cantemporarily use while in this foreign network. The mobile phoneimmediately registers this care-of address with its home agent, which isa computing device within the home network. The home agent forwardscommunications received at the mobile phone's home address to the mobilephone's care-of address while the mobile phone is in the foreignnetwork.

This approach for providing Internet connectivity to mobile resourcesdoes not scale very well, however, when there are tens of thousands, ifnot hundreds of thousands or millions, of mobile resources constantlymoving among different foreign networks. Regardless of whether a mobilephone currently has an ongoing communication session or not, the mobilephone always immediately registers with its home agent when the mobilephone travels to a new foreign network (or when it is turned on in aforeign network). A given home agent may be the home agent for a largenumber of devices, a majority of which may be traveling within foreignnetworks at any given time.

Thus, the home agent may be constantly receiving care-of addressregistrations from mobile resources that are traveling within foreignnetworks, even if most of these resources do not currently have ongoingcommunication sessions that require the home agent to immediately knowthe care-of addresses of the mobile resources. The home agent may becomeoverburdened fairly quickly. Furthermore, the networks themselves can beoverburdened, with many mobile resources constantly registering withtheir home agents as the resources traverse different foreign networks.That is, the bandwidth of the networks may be consumed by registrationcommunications, as opposed to, for instance, communications.

For these and other reasons, therefore, there is a need for the presentinvention.

SUMMARY OF THE INVENTION

The present invention relates to delaying mobile node registration witha home network of the mobile node when the mobile node moves to aforeign network. In a method of the present invention, the mobile nodehas a home network in which the mobile node has a home address. Inresponse to the mobile node moving to a foreign network, the mobile nodereceives a care-of address. Where the mobile node has no ongoingcommunication sessions, the mobile node waits to register its care-ofaddress with its home agent in the home network until the mobile nodeinitiates a communication session within the foreign network, which maynot ever occur, such that registration never occurs. The mobile noderegistering the care-of address with the home agent informs the homeagent where to forward data sent to the home address in accordance witha communication session.

A system of the present invention includes at least a mobile node, ahome network of the mobile node in which the mobile node has a homeaddress, a home agent for the mobile node within the home network, andone or more foreign networks. The mobile node receives a care-of addresseach time it moves to a foreign network. The mobile node has to registerthis care-of address with its home agent in order to receive data sentto the home address of the mobile node. However, the mobile node delaysregistration of the care-of address with its home agent where no ongoingcommunication sessions exist upon movement to the foreign network, untila communication session is subsequently, if ever, initiated by themobile node while the mobile node is still in that foreign network.

An article of manufacture of the present invention includes acomputer-readable medium, and means in the medium. The computer-readablemedium may be a recordable data storage medium, a modulated carriersignal, or another type of computer-readable medium. The means is forwaiting to register a mobile node with a home agent of a home network,upon movement of the mobile node to a foreign network, until the mobilenode initiates a communication session within the foreign network. Thus,the mobile node is not immediately registered with the home agent uponmoving to the foreign network, unless the mobile node has one or moreongoing communication sessions upon moving to the foreign network.

A mobile node of the present invention includes a communicationmechanism and a registration mechanism. The communication mechanism isto communicate with a home agent of a home network of the mobile node,to receive a care-of address when the mobile node is moved to a foreignnetwork, and to conduct communication sessions. The registrationmechanism is to delay registration of the care-of address with the homeagent until a communication session is initiated while the mobile nodeis in the foreign network, unless the mobile node has one or morecurrent ongoing communication sessions.

Embodiments of the invention provide for advantages over the prior art.For instance, mobile nodes are likely not to be engaging in ongoingcommunication sessions when they move to new foreign networks.Therefore, while the mobile nodes are not engaging in a communicationwith another node while in the foreign network, there is no need for themobile nodes to register with the home agents of their home networks.The mobile nodes, in other words, do not register with the home agentsimmediately upon moving to foreign networks. Rather, the mobile nodesonly register with the home agents later, if and when communicationsessions are subsequently initiated. However, if the mobile nodes havecurrent ongoing communication sessions when they move to a foreignnetwork, they immediately register their assigned care-of addresses withtheir home agents. Furthermore, if the mobile nodes exit their currentforeign networks without having ever initiated communication sessions,then they will never have to register with their home agents from theircurrent foreign networks.

Thus, the embodiments of the invention can decrease theregistration-oriented traffic within the networks, preventing thenetworks from becoming overburdened, as well as preventing the homeagents from becoming overburdened. For example, a given mobile node maytravel from its home network, to a number of different foreign networksin succession, and then back to its home network, while neverestablishing a communication session in any of these networks. In theprior art, each time this mobile node travels to a different foreignnetwork, it has to register with the home agent of its home network.However in this scenario, according to the present invention, the mobilenode never registers with the home agent when traveling to a differentforeign network, because no communication session is ongoing, nor is oneever initiated.

Such a decrease in registration-oriented traffic within the networksfrees up the networks for other types of traffic. Furthermore, such adecrease in registration-oriented traffic means that the home agents maybe able to handle more mobile nodes, since only the mobile nodes thatare currently engaged in ongoing communication sessions will beregistering back with the home agents upon moving to foreign networks.Still further aspects, embodiments, and advantages of the invention willbecome apparent by reading the detailed description that follows, and byreferring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings referenced herein form a part of the specification.Features shown in the drawing are meant as illustrative of only someembodiments of the invention, and not of all embodiments of theinvention, unless otherwise explicitly indicated, and implications tothe contrary are otherwise not to be made.

FIG. 1 is a flowchart of a method performed by a mobile node when movingamong different foreign networks, according to an embodiment of theinvention, and is suggested for printing on the first page of thepatent.

FIG. 2 is a diagram of a representative system having a number ofnetworks that can be traversed by mobile nodes, in accordance with whichembodiments of the invention may be practiced.

FIGS. 3A, 3B, 3C, and 3D are diagrams depicting an example of delayedmobile node registration with a home agent, when the mobile node movesto a new foreign network, according to an embodiment of the invention.

FIG. 4 is a flowchart of a method performed by a mobile node when movingamong different foreign networks, and which is more detailed than butconsistent with the method of FIG. 1.

FIG. 5 is a block diagram of a rudimentary mobile node, according to anembodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

In the following detailed description of exemplary embodiments of theinvention, reference is made to the accompanying drawings that form apart hereof, and in which is shown by way of illustration specificexemplary embodiments in which the invention may be practiced. Theseembodiments are described in sufficient detail to enable those skilledin the art to practice the invention. Other embodiments may be utilized,and logical, mechanical, and other changes may be made without departingfrom the spirit or scope of the present invention. The followingdetailed description is, therefore, not to be taken in a limiting sense,and the scope of the present invention is defined only by the appendedclaims.

Overview

FIG. 1 shows a method 100 that is performed by a mobile node when movingto a foreign network, according to an embodiment of the invention. Themobile node has a home network in which the mobile node has a homeaddress, which may be a mobile Internet Protocol (IP) address. Themobile node further has a home agent in the home network.

The mobile node moves, or travels, to a foreign network (102). Theforeign network is a network other than the home network of the mobilenode. When moving to the foreign network, the mobile node receives acare-of address (104). The care-of address of the mobile node is atemporary forwarding address, such as another mobile IP address, towhich data sent to the home address of the home node is to be forwardedby the home agent. The care-of address of the mobile node may also bethe address by which direct communication with the mobile node can beestablished while the mobile node is in the foreign network. Thus, inorder for the home agent to know the current care-of address of themobile node to which to forward data sent to the home address of themobile node, the mobile node has to register its current care-of addresswith its home agent.

If the mobile node has any current ongoing communication sessions whenit moves to the foreign network (106), then the mobile node immediatelyregisters its assigned care-of address with the home agent of the homenetwork (108). This is accomplished so that the home agent is informedwhere to continue to send data sent to the home address of the mobilenode, enabling the mobile node to seamlessly roam among differentnetworks while maintaining its current ongoing communication sessions. Acommunication session may be an Internet web site browsing session, aninstant message (IM) communication session, data, video and/or audio, avoice telephone call, and/or another type of communication session.

However, if the mobile node does not have any current ongoingcommunication sessions when it moves to the foreign network (106), thenthe mobile node does not immediately register its assigned care-ofaddress with the home agent of the home network. This is because thehome agent does not need to immediately be informed as to where toforward data sent to the home address of the mobile node, since themobile node is not currently receiving or sending data in accordancewith a current ongoing communication session. Rather, only when themobile node initiates a communication session (112), does the mobilenode later register its care-of address with the home agent of the homenetwork (108). This later registration is necessary because when themobile node does initiate a communication session, the home agent needsto know the care-of address to which to forward data sent to the homeaddress of the home node.

The method 100 is repeated each time the mobile node enters a newforeign network. The mobile node may enter a foreign network from itshome network, or from a different foreign network. The mobile node mayfurther enter a foreign network by being turned on within the foreignnetwork. It is noted that if there are no ongoing communication sessionswhen the mobile node enters a foreign network, and the mobile node neverinitiates a communication session while in the foreign network, then themobile node never registers its care-of address with the home agent ofthe home network. Rather, the mobile node continually repeats, or“spins” on, part 112 of the method 100, such that it never registerswith the home agent of the home network. When the mobile node is movedto a different foreign network, the method 100 is thus performed anew,with the mobile node never having performed registered its care-ofaddress in the previous foreign network with the home agent of the homenetwork.

As a result, a mobile node traversing different foreign networks, whilenever initiating a communication session or maintaining an ongoingcommunication session, does not overburden the home agent or thenetworks themselves with care-of address registration traffic. Oneconsequence of the mobile node not immediately registering its care-ofaddress when entering a new foreign network, however, is that the mobilenode must always be the initiator of any communication sessions withother nodes. The other nodes cannot initiate a communication sessionwith the mobile node in question, because until the mobile node hasregistered its care-of address with the home agent of the home network,the home agent does not know where to forward data sent to the homeaddress of the mobile node. In other words, the mobile node is always aclient node, and never a server node, when performing the method 100.

Technical Background

FIG. 2 shows a representative system 200 in which mobile nodes are ableto maintain communication systems while moving across differentnetworks, and in conjunction with embodiments of the invention may beimplemented. The system 200 includes networks 202A, 202B, 202C, and202D, collectively referred to as the networks 202. While just fournetworks 202 are depicted in FIG. 2, in actuality there may be hundreds,thousands, or more of the networks 202. The networks 202 may beindividual cells of a cellular network that mobile or cellular phonesand phone devices can traverse, and in which such phones and devices cansend and receive communications.

The networks 202 have agents 204A, 204B, 204C, and 204D, which arecollectively referred to as the agents 204. The agents 204 are devices,such as computing devices, which are responsible for data sent to andreceived from mobile nodes temporarily located within their respectivenetworks 202, as well as data sent to and received from mobile nodesthat have as their home networks the networks 202, as will be described.A mobile node is mobile in that it is able to traverse the networks 202,such that it is capable of moving or traveling to different of thenetworks 202. A mobile node is currently located in a given network ifit is able to send and receive data within that network. Thus, as amobile node physically moves, it is able to send data to and receivedata from different of the agents 204, such that it is in different ofthe networks 202. The networks 202 are depicted in FIG. 2 asnon-overlapping, but may overlap to some extent to guarantee that amobile node is always able to communicate with at least one of theagents 204.

Each of the networks 202 may have a number of mobile nodes, such asmobile or cellular phones, personal digital assistant (PDA)-typedevices, as well as other types of devices, which are based in thatnetwork. The network that a given mobile node is based in is referred toas the home network of the mobile node, whereas the other networks areforeign networks in relation to that mobile node. For example, themobile node 206A is based in the network 202A, such that the network202A is the home network for the node 206A, and the other networks 202B,202C, and 202D are foreign networks for the node 206A. The agent 204A isfurther the home agent of the mobile node 206A. The mobile node 206A hasa home address 208A within its home network 202A that is maintained bythe agent 204A. When the mobile node 206A is in its home network 202A,data sent to the home address 208A is forwarded to the mobile node 206Aby the agent 204A.

In the same way, the mobile node 206B is based in the network 202B, suchthat the network 202B is the home network for the node 206B, the agent204B is the home agent of the mobile node 206B, and the mobile node 206Bhas a home address 208B within the network 202B. The networks 202A,202C, and 202D are thus foreign networks for the mobile node 206B.Likewise, the mobile node 206C is based in the network 202C, such thatthe network 202C is the home network for the node 206C, the agent 204Cis the home agent of the mobile node 206C, and the mobile node 206C hasa home address 208C within the network 202C. The networks 202A, 202B,and 202D are foreign networks for the mobile node 206C.

The mobile node 206D, however, is not currently located in its homenetwork 202D in the example of FIG. 2, but rather is currently locatedin the foreign network 202C. The mobile node 206D still has a homeaddress 208D within the home network 202D, which is maintained by itshome agent 204D. (That the mobile node 206D has the network 202D as itshome network is indicated by the dotted-lined box 206D′ in FIG. 2.) Themobile node 206D has also received a temporary care-of address 210. Themobile node 206D registers this temporary care-of address 210 with itshome agent 204D of its home network 202D. Such registration is delayedin some embodiments of the invention, as has already been describedgenerally, and as is described in more detail later in the detaileddescription. Data sent to the home address 208D of the mobile node 206Dare received by the home agent 204D, which forwards the data to thetemporary care-of address 210 of the mobile node 206D.

Delayed Registration Example

FIGS. 3A, 3B, 3C, and 3D depict an example of delayed registration ofthe mobile node 206A with its home agent 204A, according to anembodiment of the invention. In FIG. 3A, the mobile node 206A has a homeaddress 208A within its home network 202A, such that it also has as itshome agent the agent 204A. The mobile node 206A then moves or travels tothe foreign network 202B, as indicated by the arrow 302, such that themobile node 206A while in the foreign network 202B is referred to as themobile node 206A′. The mobile node 206A′ receives a temporary care-ofaddress 304. However, the mobile node 206A′ does not have any currentongoing communication sessions, and therefore does not register thistemporary care-of address 304 with the home agent 204A.

In FIG. 3B, the mobile node 206A′ moves or travels to the foreignnetwork 202C, as indicated by the arrow 307, such that the mobile node206A′ while in the foreign network 202C is referred to as the mobilenode 206A″. It is noted that the temporary care-of address 304 that themobile node 206A′ had while in the network 202B was never registeredwith the home agent 204A. This is because the mobile node 206A′ did nothave any current ongoing communication sessions when first entering thenetwork 202B, and did not initiate any new communication sessions whilein the network 202B. Thus, the networks 202A and 202B do not have theirbandwidth wasted on the registration of the temporary care-of address304. Furthermore, the home agent 204A does not have to be overburdenedwith the registration of the care-of address 304.

After entering the network 202C, the mobile node 206A″ receives a newtemporary care-of address 308. However, the mobile node 206A″ does nothave any current ongoing communication sessions, and therefore does notimmediately register the temporary care-of address 308 with the homeagent 204A. In FIG. 3C, the mobile node 206A″, still in the foreignnetwork 202C, has initiated a communication session, as indicated by thearrows 312. At this time, then, the mobile node 206A″ registers thetemporary care-of address 308 with the home agent 204A of the homenetwork 202A, as indicated by the arrow 314. Registering the temporarycare-of address 308 with the home agent 204A informs the home agent 204Awhere to forward data sent to the home address 208A of the mobile node206A″ (not shown in FIG. 3C).

In FIG. 3D, the mobile node 206A″, while still maintaining thecommunication session indicated by the arrows 312, moves or travels tothe foreign network 202D, as indicated by the arrow 316, such that themobile node 206A″ while in the foreign network 202D is referred to asthe mobile network 206A′″. After entering the network 202D, the mobilenode 206A′″ receives a new temporary care-of address 318. Because themobile node 206A′″ has a current ongoing communication session, asindicated by the arrows 312, it immediately registers its new temporarycare-of address 318 with the home agent 204A, as indicated by the arrow322. This registration allows the mobile node 206A′″ to continue toreceive communications sent to the home address 208A of the mobile node206A′″ (not shown in FIG. 3D).

Detailed Method

FIG. 4 shows a method 400 that is performed by a mobile node when movingamong different foreign networks, according to an embodiment of theinvention. The method 400 is more detailed than, but consistent with,the method 100 of FIG. 1. Like-numbered parts or boxes between FIG. 1and FIG. 4 are performed at least substantially identically in themethod 400 as they have been described in relation to the method 100 ofFIG. 1.

The method 400 begins with a delayed flag being set or cleared (402),such as by the user of the mobile node that is performing the method 400of FIG. 4. The delayed flag corresponds to whether the mobile node willdelay registration with its home agent when the mobile node travels to aforeign network at a time when there are no ongoing communicationsessions. Thus, when the flag is set, the mobile node does notimmediately register with its home agent when traveling to a foreignnetwork and when there are no ongoing communication sessions. When theflag is cleared, the mobile node immediately registers with its homeagent when traveling to a foreign network, regardless of whether thereare any ongoing communication sessions or not. It is noted that 402 maybe performed at any stage within the method 400 of FIG. 4, and isdepicted as being performed at the beginning of the method 400 forillustrative convenience only.

The mobile node moves to a new foreign network (102), and receives atemporary care-of address for use while the mobile node is within thisforeign network (104). If there are any ongoing communication sessionswhen the mobile node moves to the foreign network (106), then the mobilenode immediately registers this care-of address with the home agent ofits home network (108). If there are no ongoing communication sessionswhen the mobile node moves to the foreign network (106), and if thedelayed flag is not set (404), then the mobile node still immediatelyregisters the care-of address with the home agent of its home network(108).

However, if the delayed flag is set (404), then the mobile node does notimmediately register its care-of address with the home agent of its homenetwork. Rather, the following process is performed. If a newcommunication session has not been initiated by the mobile node (110),and if the mobile node has not moved to a different foreign network(406), then the method 100 repeats at 110. If the mobile node has movedto a different foreign network (406), then the method 400 is repeatedbeginning at 104. However, if the mobile node initiates a communicationsession (110), and if the current care-of address has already beenregistered (408), then the method 400 repeats at 406. The currentcare-of address may have already been registered if the mobile node hadongoing communication sessions when first entering the foreign networkit currently is in, and/or if the delayed flag is cleared and not set.If the current care-of address has not yet been already registered(408), then it is registered with the home agent (108), and the method400 again repeats at 406.

Mobile Node and Conclusion

FIG. 5 shows a rudimentary mobile node 500, according to an embodimentof the invention. The mobile node 500 may implement any of the mobilenodes that have been described, such as the mobile nodes 206A, 206B,206C, and 206D of FIGS. 2, 3A, 3B, 3C, and 3D. The mobile node 500 mayalso perform the methods 100 and 400 of FIGS. 1 and 4 that have beendescribed. The mobile node 500 is depicted in FIG. 5 as including acommunication mechanism 502 and a registration mechanism 504. As can beappreciated by those of ordinary skill within the art, the mobile node500 may and typically will include other components, in addition tothose depicted in FIG. 5.

The communication mechanism 502 includes hardware, or a combination ofhardware and software, and enables the mobile node 500 to communicatewith other nodes and agents, such as its home agent, and thereforeenables the mobile node 500 to conduct communication sessions as havebeen described. Thus, the communication mechanism 502 is the mechanismof the mobile node 500 that receives a care-of address when the mobilenode 500 is moved to a foreign network. The communication mechanism 502may be include a wireless transceiver, for instance, to allow the mobilenode 500 to wirelessly communicate data.

The registration mechanism 502 may be implemented in software, hardware,or a combination of hardware and software. The registration mechanism502 is the mechanism of the mobile node 500 that registers the care-ofaddress received when the mobile node 500 is moved to a foreign networkwith the home agent of the mobile node 500. As such, the registrationmechanism 502 delays registration of the care-of address until acommunication session is initiated while the mobile node is in theforeign network, unless the mobile node has one or more current ongoingcommunication sessions when moved to the foreign network, as has beendescribed. In one embodiment, such delayed registration may beaccomplished only when a corresponding flag has been set, such that whenthe flag is cleared and not set, registration of the care-of addresswith the home agent is immediately performed, and not delayed.

It is noted that, although specific embodiments have been illustratedand described herein, it will be appreciated by those of ordinary skillin the art that any arrangement calculated to achieve the same purposemay be substituted for the specific embodiments shown. This applicationis thus intended to cover any adaptations or variations of embodimentsof the present invention. Therefore, it is manifestly intended that thisinvention be limited only by the claims and equivalents thereof.

1. A method comprising: in response to a mobile node moving to a foreignnetwork, the mobile node having a home network in which the mobile nodehas a home address, receiving a care-of address within the foreignnetwork; where the mobile node has no ongoing communication sessions,waiting to register the care-of address with a home agent of the homenetwork until the mobile node initiates a communication session withinthe foreign network.
 2. The method of claim 1, wherein registering thecare-of address with the home agent informs the home agent where toforward data sent to the home address in accordance with thecommunication session.
 3. The method of claim 1, further comprising, inresponse to the mobile node moving to the foreign network, where themobile node has one or more ongoing communication sessions, immediatelyregistering the care-of address with the home agent of the home network.4. The method of claim 1, further comprising, in response to the mobilenode moving to the foreign network, where a flag corresponding towhether registering with the home agent should be delayed is not set,immediately registering the care-of address with the home agent of thehome network.
 5. The method of claim 1, further comprising, setting aflag corresponding to whether registering with the home agent should bedelayed, such that registering with the home agent is subsequentlyaccomplished when the mobile node moves to a foreign network only ifthere is an ongoing communication session or when a communicationsession is later initiated.
 6. The method of claim 1, furthercomprising, clearing a flag corresponding to whether registering withthe home agent should be delayed, such that registering with the homeagent is subsequently accomplished automatically each time the mobileneed moves to a foreign network, regardless of whether there is anongoing communication session.
 7. The method of claim 1, furthercomprising: the mobile node initiating a communication session; and, asa result of the mobile node initiating the communication session,registering the care-of address with the home agent to inform the homeagent where to forward data in conjunction with the communicationsession.
 8. The method of claim 1, further comprising: the mobile nodemoving to another foreign network; receiving a new care-of address fromthe other foreign network; where the mobile node has no ongoingcommunication sessions, waiting to register the care-of address with thehome agent of the home network until the mobile node initiates acommunication session.
 9. The method of claim 1, wherein the mobile nodemoving to the foreign network comprises the mobile node being powered onwithin the foreign network.
 10. The method of claim 1, furthercomprising, the mobile node initially moving to the foreign network fromanother foreign network.
 11. The method of claim 1, further comprising,the mobile node initially moving to the foreign network from the homenetwork.
 12. A system comprising: a mobile node; a home network of themobile node, the mobile node having a home address within the homenetwork; a home agent for the mobile node within the home network; and,one or more foreign networks, the mobile node receiving a care-ofaddress each time the mobile node moves to one of the foreign networks,the mobile node having to register the care-of address received uponmoving to one of the foreign networks with the home agent in order toreceive data sent to the home address of the mobile node, wherein themobile node is to delay registration of the care-of address with thehome agent where no ongoing communication sessions exist upon movementto one of the foreign networks, until a communication session is laterinitiated.
 13. The system of claim 12, wherein the mobile node is todelay registration of the care-of address with the home agent inaccordance with a flag corresponding to whether registration with thehome agent should be delayed.
 14. The system of claim 13, wherein theflag is settable by a user of the mobile node.
 15. The system of claim13, wherein, upon the flag being set, no other node is capable ofinitiating a communication session with the mobile node, such that onlythe mobile node is capable of initiating a communication session withanother node.
 16. An article of manufacture comprising: acomputer-readable medium; and, means in the medium for waiting toregister a mobile node with a home agent of a home network upon movementof the mobile node to a foreign network until the mobile node initiatesa communication session within the foreign network, such that the mobilenode is not immediately registered with the home agent upon movement tothe foreign network unless the mobile node has one or more ongoingcommunication sessions.
 17. The article of claim 16, wherein the meansis for waiting to register the mobile node with the home agent of thehome network where the mobile node has no ongoing communication sessionsupon movement of the mobile node to the foreign network.
 18. The articleof claim 16, wherein the means is further for registering the mobilenode with the home agent, by registering a care-of address receivedwithin the foreign network with the home agent of the home network, sothat data sent to a home address of the mobile node can be forwarded tothe care-of address of the mobile node.
 19. The article of claim 16,wherein the means is further for waiting to register the mobile nodewith the home agent of the home network upon movement of the mobile nodeto the foreign network in accordance with a flag corresponding towhether registering with the home agent should be delayed.
 20. A mobilenode comprising: a communication mechanism to communicate with a homeagent of a home network of the mobile node, to receive a care-of addresswhen the mobile node is moved to a foreign network, and to conductcommunication sessions; and, a registration mechanism to delayregistration of the care-of address with the home agent until acommunication session is initiated while the mobile node is in theforeign network, unless the mobile node has one or more current ongoingcommunication sessions when moved to the foreign network.